Research and Development of U68CuCr Rail Steel

2012 ◽  
Vol 482-484 ◽  
pp. 989-995
Author(s):  
Yu Ji ◽  
Zhong Min Yang ◽  
Min Zhu ◽  
Wan Ling Zhang

According to characteristics of the marine environment corrosion, 980MPa steel were developed. After design rational chemical composition and production process, the full section hot-rolled corrosion-resistant sorbite rail steel were successfully developed. this kind of steel has fine grain size, high strength and perfect toughness. Dry-wet immersion test showed that lift of this rail is 70% longer than U75V.

2021 ◽  
Vol 1016 ◽  
pp. 1503-1509
Author(s):  
Kosuke Ueki ◽  
Soh Yanagihara ◽  
Kyosuke Ueda ◽  
Masaaki Nakai ◽  
Takayoshi Nakano ◽  
...  

The Co-20Cr-15W-10Ni (CCWN, mass%) alloy has excellent corrosion resistance and strength-ductility balance and is applied in almost all balloon-expandable stent platforms. To further reduce the invasiveness of stent placement, it is necessary to reduce the diameter of the stent. That is, both high strength and high ductility should be achieved while maintaining a low yield stress. In our previous studies, it was discovered that low-temperature heat-treatment (LTHT) at 873 K improves the elongation of the CCWN alloy. In this study, we focused on the grain refinement by swaging and static recrystallization to improve the strength of the alloy. The as-swaged alloy was recrystallized at 1373–1473 K for 100–300 s, followed by LTHT. A fine grain structure with an average grain size of 3–17 μm was obtained by static recrystallization. The η-phase (M12X-M6X type precipitates, M: metallic elements, X: C and/or N) formed during the recrystallization at 1373–1448 K. The alloys recrystallized at 1448 and 1473 K had a homogeneous structure with a small variation in the grain size. On the other hand, the alloys recrystallized at 1373 and 1423 K had an inhomogeneous structure in which fine and coarse grains were mixed. Both the strength and ductility of the CCWN alloy were improved by combining high-temperature short-time recrystallization and LTHT.


2005 ◽  
Vol 475-479 ◽  
pp. 43-48 ◽  
Author(s):  
Yunqing Ma ◽  
Jae Eun Jin ◽  
Young Kook Lee

A lot of works for developing the structural nano-materials have been performed all over the world in recent years. Severe deformation techniques like HPT, ECPA and ARB have been applied to different materials such as Al, Cu, Ti and several steels. Such techniques greatly reduced the grain size and improved the yield and tensile strengths. However, the elongation of the materials is greatly decreased due to the small amount of work hardening, and these techniques do not seem suitable for the mass production. Therefore, this study has been carried out as a fundamental research for developing austenitic steels with high strength and good elongation using a conventional rolling and annealing processes. Fe-0.1%C-10%Cr-5%Ni-8%Mn alloy was melted, homogenized, hot rolled, and cold rolled at room temperature to transform γ austenite to α ’ martensite. After that, the specimens were annealed just above its reverse transformation finish temperature (Af) to obtain the fine reversed austenite grains. The grain size of the metastable austenitic steel was successfully refined to less than 200nm by repeating rolling and annealing processes. The resultant nanocrystalline material shows not only high strength but also large elongation because the work hardening ability is enhanced by the strain-induced martensitic transformation during the tensile test.


1982 ◽  
Vol 68 (9) ◽  
pp. 1340-1347 ◽  
Author(s):  
Masatoshi SHINOZAKI ◽  
Hiroshi HASHIMOTO ◽  
Toshiyuki KATO ◽  
Toshio IRIE

2019 ◽  
Vol 237 ◽  
pp. 65-68 ◽  
Author(s):  
Hucheng Pan ◽  
Changlin Yang ◽  
Yantao Yang ◽  
Yongqiang Dai ◽  
Dengshan Zhou ◽  
...  
Keyword(s):  

2011 ◽  
Vol 339 ◽  
pp. 215-218
Author(s):  
Bin Bin Sun ◽  
Zhi Wei Jia ◽  
Hong Mei Zhang

The experiments were carried out on the φ450 hot rolling mill at the State Key laboratory of Rolling and Automatic of Northeastern University. The effect of different finish-rolling reduction on the microstructure and mechanical properties of C-Si-Mn hot rolled dual-phase steel were studied. It is found that the grain size of the ferrite would be finer with the increasing of finish-rolling reduction. Through the controlling of the finish-rolling reduction, grain size of the ferrite can be finer, so the better properties can be obtained by fine grain and sub-grain strengthened. With the low volume of lath martensite, the elongation of sample is high, the yield-strength ratio is low, and complex properties are better.


2021 ◽  
Author(s):  
Alber Sadek

Abstract IN718 has good fabricability, high strength at elevated temperature, and corrosion resistance, and it is widely deployed in many aerospace and other high-performance applications. With the molten pool rapid solidification during laser powder bed fusion (L-PBF), the resulting microstructure is anisotropic and inhibits macro-segregation. The as-built condition usually exhibits lower mechanical properties. Four different heat treatment procedures were designed and tested to study the effect of different heat treatment parameters on the type of precipitates and grain size. The investigated heat treatment procedures showed the formation of equiaxed grain size and a significant amount of γ' and γ" particles at the grain boundary in addition to primary carbide types (MC). Three types of microstructure characteristics and grain size were achieved. Coarse grain size suitable for creep application was achieved by increasing the soaking time at the aging cycle. The formation of serrated grain boundaries suitable for good fatigue and creep properties was achieved by decreasing the stress relief cycle's soaking time and temperature. Fine-grain size, which is preferable for fatigue properties, was achieved by decreasing the soaking time at the solution annealing cycle.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Yuta Fukuda ◽  
Masafumi Noda ◽  
Tomomi Ito ◽  
Kazutaka Suzuki ◽  
Naobumi Saito ◽  
...  

A cast Mg-8Al-1Zn-1Ca magnesium alloy was multipass hot rolled at different sample and roll temperatures. The effect of the rolling conditions and reduction in thickness on the microstructure and mechanical properties was investigated. The optimal combination of the ultimate tensile strength, 351 MPa, yield strength, 304 MPa, and ductility, 12.2%, was obtained with the 3 mm thick Mg-8Al-1Zn-1Ca rolled sheet, which was produced with a roll temperature of 80°C and sample temperature of 430°C. This rolling process resulted in the formation of a bimodal structure in the α-Mg matrix, which consequently led to good ductility and high strength, exclusively by the hot rolling process. The 3 mm thick rolled sheet exhibited fine (mean grain size of 2.7 μm) and coarse grain regions (mean grain size of 13.6 μm) with area fractions of 29% and 71%, respectively. In summary, the balance between the strength and ductility was enhanced by the grain refinement of the α-Mg matrix and by controlling the frequency and orientation of the grains.


2012 ◽  
Vol 535-537 ◽  
pp. 533-537 ◽  
Author(s):  
Meng Li

The paper has mainly reviewed the production process of as-cast high toughness ductile iron, analysing the effects of chemical composition, desulphurization process, nodulizing process and the craft of inoculation on the production of as-cast high toughness ductile iron.


1981 ◽  
Vol 23 (5) ◽  
pp. 321-323
Author(s):  
K. �. Safonova ◽  
A. V. Velikanov

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